This invention is an improvement of the apparatus shown and described in U.S. Pat. No. 4,152,895, issued May 8, 1979, entitled Wave Powered Motor, by the present inventor and assigned to the assignee hereof, the disclosure of which is incorporated herein by reference.
The structure described in the aforementioned prior patent employs a dome-shaped shell which may be floated in a partially submerged condition within the open sea, with the open mouth of the shell nearest the floor. This prior structure causes the surface waves to break, and captures these waves by directing such breaking waves into a vertical standpipe centrally disposed within the shell. Radially-disposed inlet guide vanes impart a rotational motion to the water entering the standpipe. The water within the standpipe flows vertically downward with a vortex motion, and is discharged through a diffuser in the area of the open mouth at the base of the shell. The energy of the waves is extracted by placing a turbine rotor within the flow in the standpipe.
Although the structure of this prior invention is very useful in extracting wave energy, it has been found that this prior structure can be adapted to alternate uses. In the open sea, where wave trains may arrive from several directions at once, there is a single resultant flux vector if the energy transport of each wave train is regarded as a flux vector. If the shell structure is tethered so as to be freely rotatable about its central axis, and a large radial fin or vane is secured to the portion of the shell extending through the surface of the sea, then the apparatus may be made responsive to the above-described resultant flux vector. It has been discovered, by analysis of wave forces on vertical walls, that such a fin will always extend radially to point in the direction of the resultant flux vector and thereby seek the lee side of the shell, that is, the forces of rotation on the shell will rotate the shell until the fin extends into the quietest (wave-free) water.
One practical consequence of this embodiment of the present invention and other embodiments to be described hereafter is that more efficient, unsymmetrical inlet guide vanes may be used even in the open sea. The resulting increase in efficiency enhances the utility of the device for use in attenuating surface waves, and in thereby locally calming the sea surface for the protection of ship moorings, drilling towers, and the like.
It is, therefore, a general object of the present invention to provide a novel and improved structure which functions to attenuate or dissipate surface waves and provide a protective calm area.
It is another object of the present invention to provide a novel and improved structure for attenuating or dissipating surface waves, which structure is partially submerged in the sea and provides a protective calm area.
It is a further object of the present invention to provide a novel and improved structure for attenuating or dissipating surface waves, which structure automatically orients itself in relation to the resultant flux vector of the waves and provides a protective calm area.